Atom movements via six-jump vacancy cycle are analysed in detail for a two-dimensional ordered alloy, AB. The diffusion coefficients, D_A and D_B, are expressible in terms of the effective jump frequency, \barν, for the six-jump vacancy cycle, and the correlation factors, f_A and f_B. By applying the theory of stochastic processes, the analytical expression for \barν is derived in terms of six individual jump frequencies of vacancy. The correlation factors, f_A and f_B, can be calculated exactly: f_A=1(π−1), f_B=π⁄(π+2).

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The interrelationship among the texture, order-disorder transformation and the mechanical properties in the permalloy with Ni₃Fe have been studied. It was found that the primary and secondary recrystallization orientations were interpreted by the special orientation relationship in the CSL expression of Σ7, Σ13b and Σ21a. The grain boundaries with such CSL structure were actually observed in the primary recrystallization structure. The ordered structure before rolling made it hard to develop the sharp cube texture after primary recrystallization.
Work hardening rate and elongation of the cube oriented permalloy were dependent on the orientation of tensile axis. Elongation of ordered permalloy with cube orientation under the tensile test was smaller than that of the disordered one. It was found in the tensile test of the ordered permalloy with cube orientation that there was a tendency for decohesion along high angle boundaries rather than low angle boundary and the tendency was enhanced by annealing under a low vacuum. The obtained results suggest that the ductility can be improved by controlling the texture.

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The present study was performed in an attempt to clarify the anomalous behavior occurring at temperatures close to the freezing point of a component metal in several liquid alloys by employing the emf technique.
By measuring emfs for liquid Pb–Hg, Pb–Sb and Zn–Sb alloys at slowly decreasing temperatures, E E zones indicated by two breaks in the emf-temperature relationship were determined.
Good similarity was observed between the compositional dependence of the E E zone and excess stability.

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The present study was performed in an attempt to confirm the existence of E E zones in liquid Pb–Bi alloys by employing emf and density measurements.
It was made clear by density measurements that the E E zones in the liquid alloys were related to the pre-freezing anomaly of pure lead and that the temperature widths of the zones were 20 to 30 K.
The compositional dependence of the E E zone was found to correlate well with that of excess stability.

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Tensile fracture processes of a unidirectionally solidified Al–Al₃Ni eutectic (an Al-matrix composite strengthened by Al₃Ni fibers) were investigated in a temperature range of 293–673 K from a microstructural point of view.
At low temperatures (≤473 K), fibers were broken in a brittle manner, leading to the formation of micro-voids at the sites of fiber break. It was suggested that local stresses around micro-voids were transmitted quickly to adjacent fibers by the matrix shear due to dislocation activity, resulting in the brittle fracture of the eutectic. In this case, the tensile strength of the eutectic was predictable from the so-called rule of mixture.
At higher temperatures (≥573 K), a local strain-concentrated band within which plastic deformation was concentrated developed across a cross-section of the specimen prior to the fracture of eutectic. In the interior of the band, fibers had been broken into short pieces in a ductile manner with local necking, and no micro-voids had been formed at the sites of fiber break. Nucleation of micro-voids was ascribed to a process in which these short fibers were pulled out from the matrix. The micro-voids grew by plastic deformation of the matrix, and the resultant fracture of the eutectic was caused by the linkage of grown voids in a ductile manner. Further, such ductile breakage of fibers embedded in the matrix was in contrast with the brittle one observed in fibers themselves taken out from the eutectic. By this result it is implied that, for an understanding of the high-temperature strength of the eutectic, the effect of the ductile matrix on the deformation and/or breakage behavior of brittle fibers should also be taken into consideration.

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The influence of annealing temperature on the mechanical properties and deformation behavior of CP–Ti and Ti–4Al–1.5Mn sheets has been investigated. Limit strains in sheet metal have been examined for strain paths between uniaxial and equibiaxial stretching. Uniaxial tensile test has been performed to determine the influence of annealing temperature on the value of strain hardening exponent, n, plastic anisotropy factor, r, and additionally the dependence of the surface roughness growth on the grain size. The relationships between the limit strains and mechanical properties have been examined.

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The effect of Zr addition to FeTi on the initial hydriding process, the pressure-composition isotherms and the microstructure was investigated. The partial substitution of Zr (1∼15 at%) for Fe, Ti or both enhanced the activation of FeTi and it hydrided at 303 K after a short incubation time without any heat treatment. All the alloys were composed of FeTi and other two phases. The FeTi phase contained almost no Zr and the changes in the plateau pressure caused by the addition of Zr were not pronounced. The other two phases contained rather large amounts of Zr and the compositions of these phases can be approximately represented by (Ti_1−yZr_y)₂Fe and (Fe_1−wZr_w)₂Ti, respectively. The former phase readily reacted with hydrogen and the latter phase did not react with hydrogen. The results obtained in this study show that the presence of the (Ti_1−yZr_y)₂Fe phase in the alloy plays a crucial role in shortening the incubation time, but decreases the hydrogen storage capacity of the alloy because the hydride of (Ti_1−yZr_y)₂Fe phase is too stable to decompose at the temperature and pressure used in this study.
An FeTi alloy with good performance was obtained by the dispersion of small amounts of the (Ti_1−yZr_y)₂Fe phase as fine particles in the alloy. That is, the rapidly cooled Fe_0.98TiZr_0.02 alloy, which is estimated to contain about 5 mol% (Ti_1−yZr_y)₂Fe phase in the alloy, was activated after a short incubation time at room temperature with its hydrogen storage capacity as large as the un doped FeTi alloy.

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Cold model experiments have been conducted with water and poorly wetting plastic beads to visually observe the role of stirring speed and the size of the impeller on the retention of beads in water. It has been observed that the exposure of the impeller surface from water initiates the incorporation of beads in water and the extent of incorporation is enhanced with increasing exposure of the impeller. The exposure of the impeller starts at a higher speed of stirring for an impeller of a smaller diameter. It has also been noticed that a deviation of these mixing parameters from the optimum level cause either the reduced number of immersed particles or the rejection of the beads and sometimes even the accumulation of the beads at the bottom of the impeller and thereby reduces the extent of incorporation of particles.

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The influence of process parameters such as the temperature, stirring speed and position of the impeller and its size on the flow pattern of molten Al-4 mass% Mg alloy controlling the retention of Al₂O₃ particles in it has been analysed. The analysis of the mixing process was carried out with the help of a model expression for the various parameters of a concentrically agitated fluid system influencing the fluid profile at the top of the crucible. The results show that in all the choices of process parameters in this work the impeller surface has been exposed except during mixing at the holding temperature of 883 K. The exposing of the impeller has been found to play a significant role in retaining the particles in the agitated slurry. However, the retention of particles has been found to be controlled by the radius of the cylindrically rotating zone, r_c, which increases with the increase in the stirring speed and size of the impeller at a given holding temperature. The retention of particles in the slurry increases so long as r_c remains below r₃, the radius of the central region of the impeller excluding the blades. In case of low holding temperature of 883 K a large retention of alumina inside the melt without any exposure of the impeller may have been possible due to the mechanical entrapment of the particles. The observations of cold model experiments have been found to be in qualitative agreement with the results obtained in the cast composites.

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